Not to mention that he'd be replacing the weakest link in the Blazer lineup. Duckworth averaged 9 and 7 on 43% shooting in the 1992 Finals with no defense. Replace him with Sabonis and you have a MASSIVE upgrade in every facet of the game, you have a go-to scoring option late when Drexler and the other Blazers start feeling the pressure and can't hit a shot for shyt, and you can play a lot more Cliff Robinson at the 4 instead of Buck Williams because you don't need Buck's rebounding anymore.
And the Bulls had a weakness at the 5 but the Lakers, Blazers, Suns didn't have the center to exploit it. How the fukk would they have countered an athletic 7'3" 290lb Sabonis with top-level offensive skills?
Considering the Blazers nearly took Game 6 from Chicago with that Buck/Duck frontcourt, just imagine how dominant they would have been with Sabonis there instead.